This invention relates to polyisocyanate prepolymers or quasi-prepolymers, and to polyurethane and/or polyurea polymers made therefrom.
Polyurethanes, polyureas and similar polymers are commercially prepared by reacting an active hydrogen-containing composition with a polyisocyanate. By varying the characteristics of the polyisocyanate and the active hydrogen-containing composition, polymers having widely varying properties can be prepared. For example, by using relatively low equivalent weight, high functionality precursor materials, rigid polyurethanes are prepared. Conversely, flexible polyurethanes are prepared by using relatively high equivalent weight, low functionality precursor materials. By using or omitting blowing agents, cellular or noncellular polyurethanes are prepared. Accordingly, polyurethanes can be prepared which are useful in a wide variety of applications.
It is common practice to reinforce the polyurethane to give it better properties. For example, in preparing flexible polyurethane foams, it is known to employ dispersions of reinforcing polymer particles in a polyether polyol in order to obtain higher load-bearing and good cell opening. Similarly, the use of reinforcing fibers and fillers is common in noncellular polyurethanes as well.
Due to the high cost of the reinforcing agents, and the processing difficulties imposed by their use, it is desirable to use the smallest amount thereof which provides adequate reinforcement, or even avoid their use altogether. In addition, it is always desirable to further improve the properties of polyurethanes.
It would therefore be desirable to provide a polyurethane and/or polyurea polymer having improved physical properties. It would also be desirable to provide a precursor material which, when reacted to form a polyurethane and/or polyurea polymer, provides improved properties, especially load bearing and/or tensile properties.